Linux - Help! I think I broke the XBMCbuntu display manager, but maybe just default login?

So I'm not exactly sure what I did, but I definitely just screwed the pooch on my HTPC and could really use some help. I'm going to describe the process of how I got here, and hopefully someone can spot where I went wrong...

I'm running a pretty vanilla XBMBbuntu machine running the release version. I was trying to install qjoypad and configure it today, pretty much just so I could play VVVVVV with my 360 controller. This was all via SSH with X forwarding enabled.

I installed two packages as part of the dependancies for compiling qjoypad:

Code:

sudo apt-get install -y libqt4-dev
sudo apt-get install -y libtst-dev

...but I had zero luck compiling on my own. I gave up and used a .deb that worked just fine. With qjoypad successfully installed, I went about launching hoping to be able to configure it right there in an X window. However...

Code:

xbmc@HTPC:/tmp$ qjoypad
No systemtrayicon available

Well damn, I seem to need a desktop. Sounds like XBMCbuntu is the place to be, so I set about starting that up....

...so let me just preface the next part by saying I'm pretty new to Linux, and maybe got a bit overzealous about how I was going to get to the desktop. Being the lazy asshole that I am, I wanted to get there via X forwarding, instead of across the room and physicall logging out of XBMC and plugging in a keyboard at the box.

I basically started trying a bunch of random commands, as follows:

Code:

xbmc@HTPC:~/.qjoypad3$ startx lightdm

Fatal server error:
Server is already active for display 0
If this server is no longer running, remove /tmp/.X0-lock
and start again.

Please consult the The X.Org Foundation support
at http://wiki.x.org
for help.

ddxSigGiveUp: Closing log
^Cxinit: unexpected signal 2
xbmc@HTPC:~/.qjoypad3$ lightdm
Only root can run Light Display Manager. To run as a regular user for testing run with the --test-mode flag.
xbmc@HTPC:~/.qjoypad3$ lightdm --test-mode
Running inside an X server requires Xephyr to be installed but it cannot be found. Please install it or update your PATH environment variable.
xbmc@HTPC:~/.qjoypad3$ exit
logout
There are stopped jobs.
xbmc@HTPC:~/.qjoypad3$ exit
logout
Connection to 192.168.1.160 closed.

Okay, no success, and I decide not to push my luck and stop running random commands. I walk over to my HTPC, plug in a keyboard, and navigate to "Exit XBMC" to get into the XBMBbuntu desktop for realz.

...shit. Screen is blank. That's odd. Well, I'm just going to SSH back in and run the reboot command, no harm done.

...SHIT. After rebooting, my HTPC is just hanging on the XBMC boot logo, and not entering XBMC OR XBMCbuntu.

And that's where I'm at right now. I'd really rather not have to backup and restore, as I JUST got everything on here working as I want it. Reinstalling it all right now would break my heart. This hasn't happened before, and I'm at a loss as to how to troubleshoot. I didn't run anything as sudo so I didn't think I could do any damage. I'd appreciate any help I could get here!